crystal structure model of MOF on a magnetic base

Large crystal structure model of a MOF


crystal structure model of MOF removed from its magnetic base

...and the same model removed from its magnetic base

Crystal structure models with magnetic features


Magnets for showing changes in a structure

Generally, our crystal structure models are made as static objects, with no ability to modify or change the structure. Usually, there are good reasons for that - most of the time, people want to illustrate a single discrete structure. If the real structure of the material doesn't change, other than to expand or contact homogeneously with temperature or pressure, then there is no real reason to have a model that changes in a way that represents that. On the other hand, materials can change drastically, for example, under external chemical attack or when undergoing a phase change. In such cases, the practical difficulties involved in illustrating that in a model are so great as to be not worth the effort.

But in some materials there are moieties that can be repeatedly removed, replaced and reinserted. In others, there are bonds that switch between similar or identical sites in the crystal. Examples of these are zeolites, which can absorb and release ionic or polar entities such as water, ammonia or metal ions.

Models that can represent changes such as this can be extremely useful when you need to easily explain the concepts to visitors or students. In order to model these changes, we can, for example, incorporate powerful neodymium magnets into some of the balls. This allows the model to hold the movable parts firmly in place when in the model, whilst being readily moveable, permitting their complete removal from the model - or even allowing their removal and replacement by a completely different chemical moiety altogether.

Crystal structure model of Wadsleyite

Octahedrally coordinated Mg2+  replaced by H+  in Wadsleyite



Magnets allowing models to fix to bases

More often, though, it is not a part of the model that you want to remove, but the entire crystal structure model from a base. Crystal strucure models and molecular models very often serve a dual purpose - most of the time, they sit decoratively in an office or laboratory, but they can also be required at other times for pedagogical purposes. Our bases can really enhance the appearance of a model, but fixing a model to a base can limit its usefulness in teaching or illustration. Often, it helps to be able to rotate the crystal so that you can see into structure from another angle, and a fixed base prevents that.

By incorporating magnets into the supports in the base, along with corresponding magnets in the atoms in the model, the crystal structure model is held very firmly in place - with strong enough magnets, most models can be held upside down, quite literally, without any danger of them falling. The magnetic bonds are readily overcome, though, and allow the model to be lifted from the base when needed for showing to visitors or students.